How to Optimize a Neural Network?

The best way to optimise a neural network is by looking at the error for training and valudation. The dynamic measurement or the time ser datom give us some good accuracy. But i'm asking myself, is there any other information that i can use to increase the accuracy of my model? And usal. This was the case also during this work that i have done, meaning that i include datam that was not in the fort off time series, but we somwo included in the nuronator. Even one layer optimised model for most of the for a lot of techniques, actually, we realize that two layer alaciem is the best model.